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RE: Digression on URI patterns (was Re: Library data diagram)

From: Young,Jeff (OR) <jyoung@oclc.org>
Date: Sun, 5 Sep 2010 12:29:30 -0400
Message-ID: <52E301F960B30049ADEFBCCF1CCAEF5909994EB1@OAEXCH4SERVER.oa.oclc.org>
To: "Thomas Baker" <tbaker@tbaker.de>
Cc: "Andy Powell" <andy.powell@eduserv.org.uk>, "Karen Coyle" <kcoyle@kcoyle.net>, <public-lld@w3.org>
Tom,

Good idea. I joined the Pedantic Web list and will reissue my comments
there. Hopefully it will spark a discussion.

Jeff

> -----Original Message-----
> From: Thomas Baker [mailto:thomasbaker49@googlemail.com] On Behalf Of
> Thomas Baker
> Sent: Sunday, September 05, 2010 11:04 AM
> To: Young,Jeff (OR)
> Cc: Andy Powell; Karen Coyle; public-lld@w3.org
> Subject: Re: Digression on URI patterns (was Re: Library data diagram)
> 
> Hi Jeff,
> 
> On Sat, Sep 04, 2010 at 10:49:54PM -0400, Jeff Young wrote:
> > > Picking up on this point...  The examples given for
> > > "303 URIs forwarding to One Generic Document" show
> > >
> > >     http://www.example.com/doc/alice
> > >
> > > redirecting to
> > >
> > >     http://www.example.com/doc/alice.rdf
> > >     http://www.example.com/doc/alice.html
> >
> > Sorry for the nitpick, but the 1st URI identifies the "generic
> document"
> > and doesn't do a redirect in this Linked Data pattern (note the /doc
> vs.
> > /id path segment). Here's the diagram we can refer to if the
> situation
> > is somehow unclear:
> >
> > http://www.w3.org/TR/cooluris/img20081203/hash_conneg.png
> 
> Right - I was not precise enough.  In [1], it is the URI
> ending in "/id/alice" that _redirects_ to "/doc/alice",
> which in turn _content_negotiates_ to "/doc/alice.rdf" and
> "/doc/alice.html"...
> 
> However, the URI cited above [2] is from the previous section on
> Hash URIs.  I believe you mean to refer to the diagram in the 303
> section [3].
> 
> [1] http://www.w3.org/TR/cooluris/#r303gendocument
> [2] http://www.w3.org/TR/cooluris/img20081203/hash_conneg.png
> [3] http://www.w3.org/TR/cooluris/img20081203/303conneg.png
> 
> > > If one were to retrieve these files using HTTP (e.g., with
"wget"),
> the
> > > files would be called:
> > >
> > >     alice.rdf
> > >     alice.html
> >
> > The concept of "file" is problematic and may be worth discussing.
The
> > Cool URIs document actually makes a point about this:
> >
> > 	"Note that a Web document is not the same as a file:"
> > 	http://www.w3.org/TR/cooluris/#oldweb
> 
> The point in Cool URIs was that on the Web, a Web Document
> is not necessarily a file but can be served up in multiple
> languages, and that "a single file, for example a PHP script,
> may be responsible for generating a large number of Web
> documents with different URIs".
> 
> My point was that when I dereference the URIs using HTTP GET,
> the download results are two files in my local filesystem,
> alice.rdf and alice.html...
> 
> Jeff:
> > I would argue that the URI pattern that appears in the Cool URIs
> > document is only useful for toy examples.
> 
> Tom points to the example:
> > >     http://www.bbc.co.uk/music/artists/a3cb23fc-acd3-4ce0-8f36-
> 1e5aa6a18432.rdf
> 
> ...to which Jeff comments:
> > Light alteration to fit my preferred pattern would result in
> something like this:
> >
> > http://example.org/MusicArtist/a3cb23fc-acd3-4ce0-8f36-
> 1e5aa6a18432/about.rdf
> 
> Tom points to the example:
> > >     http://id.loc.gov/authorities/sh85017454.rdf
> 
> ...to which Jeff comments:
> > the URI pattern I prefer would have looked something like:
> >
> > http://example.org/Concept/sh85017454/about.rdf
> 
> You are calling into question the pattern outlined in Cool URIs
> and followed by BBC and LoC - a bigger issue indeed...! :-)
> 
> Jeff:
> > Ultimately, the value of Linked Data boils down to unexpected reuse
> of
> > well-modeled resources suitable for use from diverse perspectives.
> > Regrettable URI patterns limit the domain's ability to reuse these
> > resources unexpectedly themselves. Take any of the URI examples
> you've
> > given and ask yourself how they could be enhanced to support mobile
> > browsers without crippling desktop browsers or separating themselves
> > from the Semantic Web in the process.
> >
> > There's more to this URI pattern's story, but this seems like a good
> > start. The $64 question is whether people think URI patterns are the
> > latter-day equivalent of angels on the head of a pin?
> 
> _Before_ creating millions of new URIs based on a pattern
> is an excellent time to review the pattern, and I do not
> think it is like theorizing about angels on the head of a
> pin because the behavior of real applications dereferencing
> real URIs is at stake.
> 
> We could continue to discuss this on public-lld; it is very
> relevant to the topic "library linked data"!  We can also flag
> it as an issue (and possible candidate for follow-up actions)
> in the LLD Incubator Group.  However in my view, detailed
> technical discussion should be out of scope for the Incubator
> Group per se.  Since this is relevant to more than libraries,
> this would be a great issue to raise on the Pedantic Web list
> [1].
> 
> Tom
> 
> [1] http://groups.google.com/group/pedantic-web
> 
> --
> Thomas Baker <tbaker@tbaker.de>
> 
Received on Sunday, 5 September 2010 16:30:01 GMT

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